Cutting ability and durability of surgical blade fabricated from biocompatible Zr-based bulk metallic glass

A biocompatible Zr₅₄Al₁₇Co₂₉ bulk metallic glass (BMG) becomes a potential candidate for medical device materials due to its excellent properties; however, the effort to investigate the material performance in medical devices has never been attempted. Surgical blades were developed from Zr₅₄Al₁₇Co₂₉ BMG composition using different sizes of plates to address the microstructural variation. Their cutting abilities were investigated using a designed indentation-cutting rig for sharpness tests and compared to commercial carbon steel (CS) blades. While the fully amorphous structure was confirmed in a 2 mm BMG, the presence of nanocrystal phases was implied in the 3 mm BMG. The BMG blades showed extremely higher cutting-edge quality compared to the commercial ones. In addition, the sharpness improvement was shown in 2- and 3-mm BMG blades with the blade sharpness index (BSI) of 0.29 and 0.34 compared to commercial blade BSI of 0.37. The BMG blades also showed good durability indicated by the higher edge resistance from deformation. These phenomena were determined by the absence of grain boundary and dislocation of BMG thus performing a higher elastic strain than the crystalline material to avoid plastic deformation on the extremely small cross-sectional area of the cutting edge during substrate incision.